Earnings Per Share - Reconciliation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings per share
Net income attributable to TDS shareholders used in basic earnings per share	$ 18	$ 46	$ 110	$ 119
Noncontrolling interest adjustment	(1)	0	(2)	(2)
Net income attributable to TDS shareholders used in diluted earnings per share	$ 17	$ 46	$ 108	$ 117
Weighted average number of shares used in basic earnings per share (in shares)	115	112	114	112
Effects of dilutive securities (in shares)	1	2	2	1
Weighted average number of shares used in diluted earnings per share (in shares)	116	114	116	113
Basic earnings per share attributable to TDS shareholders (in dollars per share)	$ 0.15	$ 0.41	$ 0.96	$ 1.06
Diluted earnings per share attributable to TDS shareholders (in dollars per share)	$ 0.15	$ 0.41	$ 0.93	$ 1.04
Common Shares
Earnings per share
Weighted average number of shares used in basic earnings per share (in shares)	108	105	107	105
Series A Common Shares
Earnings per share
Weighted average number of shares used in basic earnings per share (in shares)	7	7	7	7